Ben Stiller's latest film Tropic Thunder remained top of the North American box office this weekend.

It saw off competition from The House Bunny and Death Race to gross $16.1 million for Dreamworks.

Tropic Thunder, which also boasts Robert Downey Jr and Jack Black among its big-name stars, portrays the hilarious consequences of a bunch of war movie actors in the jungle entering into a real gun fight with drug bandits.

The House Bunny, by contrast, is a much more girly affair. Anna Faris is a former Playboy bunny who has to deal with, well, a bunch of sorority girls. It took $15.1 million.

The top three was rounded off by Death Race, in which Bank Job star Jason Statham is  shockingly enough  a man sent to prison for a crime he did not commit. Thrills ensue, especially for Ian McShane fans.

Heath Ledger's fascination continues for another week with The Dark Knight down two places to four, while animated feature Star Wars: The Clone Wars was also down two to round off the top five.